Timing recovery is important for detecting a digital signal received in a communication link. It enables the determination of a correct sampling time of the received signal. Most of the timing recovery algorithms are based on zero-crossing information (in time domain) or high frequency components (in frequency domain) of the received digital signal. The high frequency components of the received signal are sensitive to attenuation caused by filters or other devices in the communication link. As such, in conventional methods the baud rate of the signal is normally kept sufficiently low that the bandwidths of such filters or devices still permit effective timing recovery. Such methods, however, limit the baud rate of the signal and do not achieve desirable spectral efficiencies.
There is therefore a need for an improved method and apparatus for timing recovery convergence.